Malicious PDF — malware analysis report

Static analysis result for SHA-256 3a9c4d6cdb97efe7…

MALICIOUS

PDF

76.7 KB Created: 2021-04-19 06:52:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-23
MD5: 942d5a81b6331c1dedbd8130410d9b27 SHA-1: 23e823ad04f339921090b136f7d94ab0ddbffa7c SHA-256: 3a9c4d6cdb97efe7f037898e791487bb7ecf566f3fac468e481e6b33ef93b65f
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF file was detected as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. It contains a large number of external links, many pointing to disposable hosting services, suggesting a link farm or SEO manipulation tactic. One URL, https://midufefew.ru/strik?utm_term=possessive+pronouns+quiz+spanish, is directly embedded and appears to be the primary lure. No scripts were extracted, but the PDF structure itself is used to host the malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://midufefew.ru/strik?utm_term=possessive+pronouns+quiz+spanish PDF link annotation
    • http://kidiwutimako.mygamesonline.org/60827338152.pdfIn PDF document text
    • https://revunipaletofux.weebly.com/uploads/1/3/0/8/130874393/8544094.pdfIn PDF document text
    • https://bevifosadorafot.weebly.com/uploads/1/3/1/8/131856546/xutirumoxuwowerozi.pdfIn PDF document text
    • https://sobapeseg.weebly.com/uploads/1/3/1/0/131070394/jisapu.pdfIn PDF document text
    • http://dutewokoke.22web.org/5662951822.pdfIn PDF document text
    • https://zabugejagovim.weebly.com/uploads/1/3/1/6/131637755/6412035.pdfIn PDF document text
    • http://tejasatobes.medianewsonline.com/articulo_113_de_la_constitucion_mexicana_resumido.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://xumusemowujev.epizy.com/difference_between_synchronous_and_asynchronous_counters.pdfIn PDF document text
    • http://newotev.rf.gd/61106782612.pdfIn PDF document text
    • http://gorevifero.epizy.com/design_patterns_in_java_android.pdfIn PDF document text
    • http://texavit.epizy.com/belgium_visa_application_form_dubai.pdfIn PDF document text
    • http://doganaxagigub.rf.gd/dokit.pdfIn PDF document text
    • http://gumofiwulova.epizy.com/giviw.pdfIn PDF document text
    • https://52f9d6e5-2fd5-4906-a030-4d12f703b62a.filesusr.com/ugd/297ecd_0845382c8be34933b76df420ec82a5c6.pdf?index=trueIn PDF document text
    • http://reronagut.epizy.com/73398521966.pdfIn PDF document text
    • https://72a23b54-95c1-47c0-80d6-f7b1310faeb8.filesusr.com/ugd/65b209_5e045f14480c4a67a6581fffd7b79445.pdf?index=trueIn PDF document text
    • https://f06ae689-34e6-4fd9-b749-a5985747e370.filesusr.com/ugd/4117a9_31b11e647dec42a19e7bba2d61e200bf.pdf?index=trueIn PDF document text
    • https://156bb51f-0b62-477f-88ca-8620af00812b.filesusr.com/ugd/e3ff21_a7198d91616142f28ced2fe93c7c151e.pdf?index=trueIn PDF document text
    • https://878ee1be-828d-48b9-a24a-84283cf66a1c.filesusr.com/ugd/86936c_73af580730094a23b6b6023c9d74c216.pdf?index=trueIn PDF document text
    • https://4cf2acc4-d143-4013-a78d-f21de0873c4f.filesusr.com/ugd/e4636f_306e075b97104645ae69a2088791399e.pdf?index=trueIn PDF document text
    • https://ff5ab256-a407-4697-91b9-141751226614.filesusr.com/ugd/4205e4_48f924a686bb40febbd5390b9914a45a.pdf?index=trueIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ecfc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECFC 5112 bytes
SHA-256: 8eba5b14af888e578d449a051a7ab617840a24bdc258ad5d001ae064eabf8a9c
font_01_sfnt_off0000fe6f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE6F 11588 bytes
SHA-256: 1d649449ec67ea6c6f75856d1b03377d47046a102071f1dab5212284699ee320